An exhaust gas purifying catalyst is formed by coating a substrate made of ceramics or the like with a catalyst coating layer containing a refractory inorganic oxide and a noble metal such as Pd, Pt, Rh, and others. Such an exhaust gas purifying catalyst is known to employ a technique of forming the catalyst coating layer into a two-layer structure including an inside layer containing Pd and an outside layer containing Rh in order to improve catalytic performance (see Patent Literature 1).
Patent Literature 1: Unexamined Japanese Patent Publication No. 7-60117